Overview of Structures¶

A STRUCT groups stored fields with member functions and nested declarations. It is a value type: constructing, copying, moving, and destroying the structure also handles its fields.

Fields and members¶

::point STRUCT
{
  .x VAR I32;
  .y VAR I32;

  .sum FUNCTION() CONST: I32
  {
    RETURN .x + .y;
  }

  ::origin FUNCTION(): point
  {
    RETURN point();
  }
}

A leading . declares or accesses an instance member. Inside .sum, .x is the x field of THIS. A leading :: declares a name nested in point but not attached to an instance.

Receiver access¶

.read FUNCTION() CONST: I32
{
  RETURN .x;
}

.reset FUNCTION() MUT
{
  .x := 0;
  .y := 0;
}

The suffix expresses the receiver category. CONST permits read-only access, while MUT permits mutation. The compact suffix uses the same semantic model as an explicit @THIS ... THISTYPE parameter.

Structure properties¶

::unique_owner STRUCT MOVE_ONLY
{
  .allocation VAR MUT->BYTE;
}

Structure modifiers can constrain generated special operations or request contracts such as ANTESTATAL, SERIALOID, NONSTATIC, and STRINGLIKE. POLYMORPHIC and VIRTUAL_POLYMORPHIC opt a structure into runtime inheritance behavior, while FINAL prevents further derivation. See Inheritance for base declarations, virtual functions, and RTTI casts. The IBC_STRUCT declaration provides C-compatible field order and padding for binary interfaces that require those layout properties.

For an anonymous record whose type comes from its named initializers, use a composite literal. Composites support ordinary field access and compile-time reflection.

Public field reflection¶

Public Field Reflection provides field counts, names, declared types, and access by compile-time name or index through PUBLIC_FIELD_*. Only directly declared public instance fields are included, in declaration order. Private and inherited fields are excluded.

Reference¶

See the Structures Reference for all receiver categories, every modifier, generated-operation effects, nesting, and the IBC_STRUCT layout contract.